Single-gas-path rotating mechanism

The utility model belongs to the technical field of rotating tools, and discloses a single-gas-path rotating mechanism which comprises a mounting seat, a bearing assembly, a motor and a rotating joint, and a first bearing is arranged in a through hole of the mounting seat; the bottom of the bearing assembly penetrates through the through hole of the mounting base, the first bearing is tightly arranged on the periphery of the bearing assembly in a sleeving mode and used for supporting the bearing assembly, a bearing cavity is formed in the top of the bearing assembly, a workpiece is placed in the bearing cavity, and a first channel is formed in the bearing assembly; the motor is arranged below the bearing assembly, a transmission assembly is in transmission connection between an output shaft of the motor and the bearing assembly, the output shaft of the motor is provided with a second channel, and the bearing cavity, the first channel and the second channel are communicated to form a vacuum channel; the rotati